Guide for dentists&#39; drills



April 20, 1954 s. ROSENBERG 2,675,615

GUIDE FOR DENTISTS' DRILLS 7 Filed Nov. 24, 1952 2 Sheets-Sheet l IMVL-N D aid/Leg, 801 130:501

ATTDRNEYSI,

April .1954 s. ROSENBERG 2,675,615

GUIDE FOR DENTISTS' DRILLS Filed Nov. 24, 1952 2 SheetsSheet 2 17 ii I 2 VIM 72W ATTORNEYS:

Patented Apr. 20, 1954 UNITED STATES PATENT OFFICE Claims priority, application Great Britain July 21, 1952 7 Claims.

This invention relates to dental instruments, and more particularly to a device for use with a dentists drill.

When fitting a crown or inlay to a patients tooth, the dentist is required either to make drillings in the stump which are parallel to one another, or which taper upwardly.

One of the objects of this invention is to provide an attachment for a drill which will ensure absolute parallelism in the movements of the drill head or controlled movements which ar at an angle to the normal and such as will enable converging cuts to be made on the outside of a tooth.

Broadly stated the device according to my invention comprises a plate adapted for insertion in a patients mouth and providing an anchorage for a guide arm or other element which is adapted for pivotal connection to the drill.

In carrying out the invention the guide element may consist of a radius arm which is pivotally connected at one end to the drill conveniently to 2. lug formed at the head or end of the drill and at its other end is formed with a pin for insertion in one or other of two sockets on the anchorage plate. The two sockets may be formed integrally with a bush which is freely mounted on a spindle 13 fast with the plate, th two sockets being offset so as to give different positions of operation for the radius arm.

The invention is illustrated in the accompanying drawings in which:

Figure 1 is a perspective view showing the parts in their position of use.

Figure 2 is a View showing the parts dispersed.

Figure 3 is an under plan view of the anchorage plate.

Figure 4 is a plan view and Figure 5 a side elevation (enlarged scale) showing an alternative embodiment of a guide attachment for a dentists drill in accordance with the invention.

Figures 6 and 6 are detail views.

Figures '7 and 8 are elevations illustrating two forms of survey pin.

Referring to the drawings, a guide device or attachment for use with a dentists drill, to enable drillings, or similar cutting operations to be performed within the patients mouth with a considerable degree of accuracy, essentially comprises a part adapted for insertion in the patients mouth, a guide arm or arms adapted for connection at one end to the drill and at the other end to the insert plate.

In the drawings, A indicates generally the arm of the drill, which includes a head H of standard pattern and adapted to receive the usual burr or drill B. P indicates a plate, hereinafter termed the anchorage plate, which the operator place in the mouth of the patient and which as shown in Figure 3 is specially constructed in each case to t the individual arch (upper or lower) in the particular patient on whom it is desired to operate.

The guide device shown in Figures 1 and 2 comprises an arm I having a pin 2, at one end, which in use is dropped into position in one or other of two sockets shown at 3 and 4, formed in lugs 5 and 6 integral with a bush element 1. The bush element 1 is itself free to oscillate about a centre provided by an internally screwed spindle 8, which is fast on the plate P. Th spindle 8 is integral with a base 9 and in practice the spindle 8 is moulded integrally with the anchor plate P which may be formed of plastic or other suitable material.

It will be appreciated therefore that the sockets 3 and 4 provide a hinge centre for the guide arm i and since the lugs 5 and 6 are offset vertically in relation to each other, there is available to the operator alternate mountings at different levels for the pin 2 of the guide arm I The bush 7 is detachably secured to the spindle 8 and for this purpose the latter is provided with a flange if! on which the bush l is seated, being held in position by means of a screw i 2 with a flanged head.

At its other end, the guide arm I is provided with a screw hole I i to receiv the threaded end of a hinge pin i3 for the drill, the head H of the drill :being formed with a bracket I l having a vertical drilling to receive the hinge pin :3.

Since the hinge pin i3 is parallel with the pin 2, this will ensure that any movement of the drill head H is in a plane parallel with the spindle 8 on the anchorage. In use, when the guide device is assembled, the drill head H can be moved through an are freely relatively to its anchorage as permitted by the guide arm I and in effect therefore the drill spindle It can be moved anywhere within the geometric limits of the assembly, but because of the parallelism of the axes l3, 2 and i, the drill will always remain parallel with the centre spindle 8. When performing an operation on a patients teeth, the anchorage plate P having been inserted into the patients mouth, the arm I will ensure that the movement of the drill head is controlled, thereby enabling the operator to make parallel cuts in the same or different teeth.

It will be understood that the device of my invention can be used in conjunction with any of the common types of dental hand piece: except the straight hand piece the right angle in which by means of gears the burr is held at right angles to the long axis: and the contra angle in which by means of another bend in the neck of the right angle hand piece the burr or drill is held at approximately 120 to the long axis.

In cases where it is desired to perform operations on the side of the tooth, I may use a modifled form of guide device which enables the drill to work at right angles to the spindle 8 of the anchor plate, this movement being necessary when the sides of a tooth are to be reduced, as is normally the practice, by using discs (diamond, carborundum or sandpaper) to cut away the outer surface of the tooth as distinct from cutting cavities Within the tooth. An arrangement suitable for this purpose is shown in Figures 4 and 5.

In order to provide for additional maneuverability and room for'the spindle of the drill carrying the disc 30, the guide arm is formed in two portions I! and I8, pivoted to one another by a pin 9. The part I8 carrying the pin 2 for insertion in one or other of the sockets 3 and 4 of the anchorage plate mounting. The other portion I! is pivotally secured at 20 to a swing nut 2| (see also Figures 6 and 6 the swing nut 2 i as hereinafter explained, being interchangeable and for this purpose the swing nut 2 i is releasably secured to the drill head by means of a fixing pin i3 which is carried in the bracket [4 on the drill head H. For normal purposes it is sufiicient to provide two swing nuts as shown in Figures 6 and 6 giving operating angles with a variation of 5.

The nut shown in Figure 6 is provided with a threaded hole 22 at right angles to a pin 23 by which it is pivotally secured to the link I! of the guide arm I. In the alternative form shown in Figure 6 instead of the drilling 22 being at right angles to the screw pin 23, it is at an angle of 5 thereto. When the first swing nut (Figure 5 is used, the disc will cut parallel to the swivel spindle 8 and by cutting with different sides of the disc 21. tooth can be ground so that its sides are parallel. Using the second swing nut (Figure 6 the sides of the tooth can be ground with a 5 taper.

To enable the operator to determine that cuts made in the patients teeth are parallel or at the required angularity I provide a survey pin. This may consist of a separate unit as shown in Figure 7 and comprises an arm piece I having a pin 2 for insertion in the socket 4. Fast with the free end of the arm I is a fine needle 35 constituting the survey pin. To use the survey pin 35 the hand piece H is detached by removing the fixing pin l3.

In practice I have found it more convenient to incorporate the survey pin 35 with the radius arm I (Figure 1) or Il-IB (Figures 4 and 5). For this a groove 36 is cut in the vertical face of the radius arm portion I1, the pin indicated at 35 being releasably held by a clamp plate 31 and screw 38.

I claim:

1. In a dental instrument, the combination of a drill including a drill member, an anchor plate for insertion in a patients mouth having a spindle, a guide arm for the drill, a bush element mounted on said spindle, said bush element having at least one socket to receive a pivot pin on the guide arm, and means at the other end of said guide arm by which it is pivotally connected to the head of the drill member.

2. A dental instrument as set forth in claim 1 wherein the bush element is formed with two sockets to receive the pin on the guide arm, said sockets being arranged at positions spaced vertically apart to provide alternate mountings for the guide arm.

3. A dental instrument as set forth in claim 1 wherein the guide arm is pivotally connected to the drill head by means of a threaded pivot pin which is carried in a hole formed in a lug on said head.

4. A dental instrument as set forth in claim 3 in which the guide arm is connected to the drill head by a sewing nut onto which the pivot pin screws, the nut being secured by a releasable connection with the guide arm.

5. A dental instrument as set forth in claim 4 in which the swing nut is secured by a screw pin to the guide arm.

6. A dental instrument as set forth in claim 5 in which the axes of the pivot pin connecting the swing nut to the drill head and of the screw pin by which it is secured to the guide arm are at an angle other than a right angle.

'7. A dental instrument as set forth in claim 6 comprising a guide arm in two portions articulated one to the other.

References Cited in the file of this patent UNITED STATES PATENTS 

